Reciprocating-piston engine.



H. PILLING.

'RECIPROCATING PISTON ENGINE.

APPLICATION FILED MAY I, I9I5.

Patented Sept. 7, 1915.

3 SHEETS-SHEET 1.

I iii/2mg H. FILLING.

RECIPROCATING PISTON ENGINE.

APPLICATION FILED MAY I, l9l5.

latvntcd Sept.

3 SHEETS-SHEET 2.

wit-5565' H. FILLING.

RECIPROCATING PISTON ENGINE.

APPLICATION FILED MAY 1. 1915.

Patented Sept. 7, 1915 3 SHEETSSHEET 3.

Jill/672E 77/127 BECIPROCA'1ING-PISTON ENGINE.

2 Specification of Letters Patent.

Patented Sept. 7,, 1915.

Application filed May 1, 1915. Seria1No.25,277.

To all whom it may concern:

Be it known that I, HENRY FILLING, a subject of the King of Great Britain, residing in Chorlton-cum-Hardy, England, have invented certain new and useful Improve ments in ReciprocatingPiston Engines, of which the following is a specification.

This invention relates to reciprocating piston engines using steamv or other expansible fluid as the working fluid, and while it is applicable to engines of ordinary design in which the main exhaust is situated at or near the working fluid inlet end of the cylinder, it is particularly designated to be applied to uniflow designed engines in which the working fluid is normally or mainly exhausted through a port or ports in the cylinder wall uncovered by the piston toward the end of the expansion stroke, and the invention will therefore be hereinafter described mainly with respect to such engines, and for convenience it will be assumed that the working fluid is steam.

The object of the invention is to prevent the pressure of the steam shut up in the em gine cylinder, after the main exhaust ports are closed reaching a dangerous or undesirably high value, such as might occur if the pressure of the steam in the cylinder at-the moment of closure of the exhaust ports should for any reason exceed the normal value for which the cylinder clearance space has been proportional.

According to this invention such excessive compression pressure is prevented by providing an escape valve or valves communicating with the cylinder at or near the inlet end, so actuated and controlled as to be automatically brought into action when the exhaust passage pressure of the engine exceeds a predetermined value, the said valve or valves being kept closed during the period of admission and expansion of the steam.

The invention is illustrated somewhat diagrammatically in the accompanying drawings as applied to a central exhaust uniflow reciprocating steam engine, Figure 1 being a transverse section through one of the cylinder heads; Fig. 2 a side viewand Fig. 3 a plan view of the cylinder; Fig. 4 is a view corresponding to Fig. 2 showing a modification in which the steam passes from the engine cylinder auxiliary clearance chambers; and Figs; Sand 6 are views corresponding with Fig. 1 showing. modified forms of gear for forcibly openingthe compression pressure control valve.

The cylinder head or cover 1 is provided, [with a steam inlet valve 2 of any known ".type, which admits steam through the inlet 1 port 3 to the cylinder 24 of which 4 is the piston rod. The cam shaft 15, which is driven by and at the same speed as the crank shaft of the engine, is provided with cams 15 one such cam being provided for the compression control devicein each cylinder head. The cam 15 engages with the roller 16 on the lever 17 which oscillates about the pivot 19. i

The control cylinder 9, the piston 13 of which is held up by the spring 14, communicates on its under side by means of the pipe 18 with the'exhaust passages 22 of the cylinder 24.

The piston 13 of the control cylinder 9 is connected by the rods and links 10, 11, 23 and 12 with a stepped wedge or pecker block 8, one face of which bears against a cap 7 attached to the spindle of the control-valve 5. The opposite face of the pecker block 8 is usually serrated or furrowed so as to engage with the point 17 a of the oscillating lever 17.

The valve 5 is inserted in the cylinder cover 1 and communicates with the interior of the cylinder 24 by means of the port 6,

and also with the exhaust passages 22 by means of the pipe 21. The valve is kept closed by the spring 20, except when forciblv opened. When opened a. passageway exists from the cylinder through the port 6 and the pipe 21 to the exhaust passage 22.

Alternatively, as shown in Fig. 4, the pipe 21 may be part of or connected with an auxiliary clearance space 25 situated either outside the cylinder head as shown in the drawing or alternatively within the cylinder head. The steam from the cylinder 24 is admitted during the return stroke of the main engine piston to such clearance space or spaces, while the valve 5 is held open.

The position of the pecker block 8 is determined by the movement of the control piston 13 the position of which-is determined by the pressure on its under side which, again, is practically the same as the pressure in the exhaust passage 22.

When the engine is at work the cam 15 causes the point 17 of the lever 17 to be pressed toward the pecker block 8, once in each revolution of the engine crank shaft. If the pressure in the exhaust passage 22 is sufiiciently low, the position of the ecker block 8 will be such that the point 14 will not come in contact with the pecker block 8, and the valve 5 will therefore remain always closed. -On the other hand, if the pressure in the exhaust pipe 22 rises above some predetermined value, the block 8 will be raised and its shape is" suchthat the point 17 will then come in contact with it once in each revolution of the engine, and force open valve 5, thus allowing steam to pass from the engine cylinder 24 by way of port 6 through the valve 5 and pipe 21 to the exhaust passage 22, or alternatively to the auxiliary clearance chamber 25 shown in Fig. 4.

The period during which this valve 5 remains open depends upon the position of the block 8, andtherefore .upon the pressure in the exhaust-passage 22, and is so arranged that as this pressure increases, orin other words as the vacuum decreases, the valve 5 will remain open for a longer period, so that the final closing of all steam exits from the cylinder 24 becomes later as the exhaust pressure increases; in this way the pressure to .which the steam is compressed by the main piston of the engine on its return stroke is not allowed to exceed a convenient and safe value.

The cam 15 is so placed on the shaft 15 that the valve 6 is not opened until after the main exhaust ports of the engine have been uncovered by the movement of the engine piston, so that the expansion of the steam during the outgoing movement of the piston is not interfered with.

In the modified construction of Fig. 5 an eccentric 33 mounted on the shaft 15 drives a rod 34 the point 35' of which engages the cap 8 which is attached to the valve 5. The pist0n13 of the pressure control cylinder 9 operating through the rods and links 10, 11, 12 acts upon a lever 27 fulcrumed at 26 and connected by a rod 30 with a lever 28 fulcrumed at 29. The eccentric 33 is hung from one end of the lever 27 by a rod 31 and the rod 34 connected with the eccentric is suspended from the lever 28 by a rod 32. As the pressure in the cylinder 9 increases the eccentric 33 is rotated in a clockwise direction, as indicated by the ar-' row, and the rod 34 is consequently lowered bodily so thatthe point of the rod will engage the inclined serrated face of the cap 8 at a lower position and will hold the valve 5 open for a longer period.

In the modified construction of F ig.- 6 the eccentric 33 opens the valve 5 by means of the rod 37 the point 38 of which engages the shiftable pecker block 8. .This particular construction is designed to maintain the thrust on the valve head or cap 7 approxlmately central under all conditions. It Wlll be seen that as the pressure in the exhaust branch22 increases, the eccentric 33 is rotated in a clockwise direction and the pecker block 8 lifted upward, thus attaining the same general result as the mechanism of Fig. 5.

Having thus described the nature of this invention and the best means I know of carrying the same into practical effect, I claim i 1. In a reciprocating piston engine in which the main exhaust ports are closed before completion of the return stroke of the piston, an auxiliary exhaust valve, and means operative when the steam pressure in the main exhaust passage of the engine exceeds a predetermined value, to automatically and mechanically open said valve, during a portion of the return stroke of the piston.

2. In a reciprocating piston engine of the type described, an auxiliary exhaust valve, and means controlled by the pressure in the main exhaust passage of the engine for periodically and mechanically opening said valve when the steam pressure in the main exhaust passage of the engine exceeds a predetermined value.

3. In a reciprocating piston engine of the type described, the combination of a cylinder having a main exhaust passage, an auxiliary clearance space, and an auxiliary exhaust valve having a passage leading to said auxiliary clearance space, and means operative when the steam pressure in the main exhaust passage exceeds a predetermined value, to automatically and mechanically open said valve.

4. In a reciprocating piston engine of the type described having main exhaust ports, an auxiliary exhaust valve, and means for mechanically opening said valve and holding the same open for a period which increases as the main exhaust pressure of the I engine increases.

5. In a reciprocating piston engine of the type described, a compression pressure control valve, and means controlled by the main exhaust pressure of the engine for opening said valve once during each revolution of the engine embodying a thrust member having means for mechanically operating it from the engine crank shaft.

6. In a reciprocating piston engine of the type described,. a compression pressure control valve, and means for'mechanically opening it periodically embodying a thrust member operative from the crank shaft of the engine, a wedge or pecker block interposed between the valve and said thrust member, and means for positioning said block according to the exhaust pressure of the engine.

7. In a reciprocating piston engine of the type described, a compression pressure control valve, driving mechanism for opening said valve, and means embodying a relatively shiftable thrust rod and valve actuat- 5 ing. member interposed between the said valve and driving mechanism for determining the period of opening of said valve.

In testimony whereof I have signed my name to this specification in the presenoeof two subscribing witnesses.

HENRY FILLING.

Witnesses:

'WM. STARK,

W. C. Bimwsrnn. 

